One of the limiting factors in the continuing evolution toward smaller device semiconductor feature size and higher density has been the stringent requirements placed on photolithographic processes as feature sizes have decreased. Various proposals for improving feature resolution having included schemes for reducing a resist layer thickness.
Another limiting factor in manufacturing features with smaller feature sizes is the accuracy of etching and an etching resistance of an etching mask to prevent enlargement of an opening when attempting an anisotropic dry etching process. Prior art processes have generally formed an inorganic hardmask over a substrate followed by forming and patterning an overlying resist layer. The hardmask is then separately etched through a thickness according to the patterned resist mask prior to etching the substrate.
Another problem with conventional photoresists is that photoresist materials are frequently susceptible to chemical change by small amounts of chemical contaminants. For example, in immersion lithography, the photoresist may be contaminated by a immersion solution, leading to alteration of a resist profile or etching resistance.
There is therefore a continuing need for improved lithographic processes and materials in the integrated circuit manufacturing art.
It is an object of the present invention to provide an improved lithographic patterning process including an improved hardmask and method for patterning the same.